Catalytic Asymmetric Construction of the Tryptanthrin Skeleton via an Enantioselective Decarboxylative [4 + 2]
Guang-Jian Mei1, Chen-Yu Bian1, Guo-Hao Li1
1School of Chemistry and Material Science, Jiangsu Normal University , Xuzhou 221116, China.
Abstract:
The first catalytic asymmetric construction of the tryptanthrin skeleton has been established, taking advantage of a palladium(0)/chiral ligand-catalyzed enantioselective decarboxylative [4 + 2] cyclization of vinyl benzoxazinanones with isatins. This reaction has not only provided a direct and efficient method for constructing chiral tryptanthrin skeleta in high yields and excellent enantioselectivities (up to 97% yield, >99% ee) but also represents the first catalytic asymmetric decarboxylative cyclization of vinyl benzoxazinanones with isatins.
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